利索-全球专利检索

  1. 登录
  2. 注册

搜索结果

6 条记录 (耗时 0.017 秒)

    Optical fiber and optical transmission system
    1.
    发明授权
    Optical fiber and optical transmission system 有权

    公开(公告)号：US11366266B2

    公开(公告)日：2022-06-21

    申请号：US16623608

    申请日：2018-07-03

    申请人： NIPPON TELEGRAPH AND TELEPHONE CORPORATION

    发明人： Yuto Sagae ,  Kazuhide Nakajima ,  Takashi Matsui

    IPC分类号： G02B6/02 ,  G02B6/036 ,  H04B10/80

    摘要： An optical fiber includes a core, a first clad that is provided on an outer circumferential portion of the core and has a refractive index lower than that of the core, and a second clad that is provided on an outer circumferential portion of the first clad and has a refractive index lower than that of the first clad. In the optical fiber, a mode field diameter at a wavelength of 1.55 μm is equal to or greater than 11.5 μm, a cutoff wavelength is equal to or less than 1.53 μm, a bending loss at a bending radius of 30 mm and a wavelength of 1.625 μm is equal to or less than 2.0 dB/100 turns, and a delay time of transmission light per unit length at a wavelength of 1.55 μm is equal to or less than 4.876 μs/km.

    Hole assisted optical fiber
    2.
    发明授权
    Hole assisted optical fiber 有权

    公开(公告)号：US11860405B2

    公开(公告)日：2024-01-02

    申请号：US17641061

    申请日：2019-09-18

    申请人： NIPPON TELEGRAPH AND TELEPHONE CORPORATION

    发明人： Saki Nozoe ,  Nobutomo Hanzawa ,  Yuto Sagae ,  Kazuhide Nakajima ,  Kyozo Tsujikawa

    IPC分类号： G02B6/02 ,  G02B6/032 ,  G02B6/036

    CPC分类号： G02B6/02347 ,  G02B6/02361 ,  G02B6/02366 ,  G02B6/032 ,  G02B6/036

    摘要： An object of the present invention is to provide an HAF having a structure in which the number of air holes is decreased to be smaller than that of a PCF and Rayleigh scattering loss may be more reduced than that in the existing HAF. The HAF according to the present invention includes a core portion having a uniform optical refractive index; a cladding portion having a uniform optical refractive index and surrounding the core portion; and a plurality of air holes arranged in two layers at positions configuring hexagonal closest packing excluding the core portion within the cladding portion along a longitudinal direction of the hole-assisted fiber, wherein a center-to-center spacing of the air holes is a sum of a radius Rin of an inscribed circle inscribed in the air holes in an inner layer and a radius d/2 of the air hole, and a radius “a” of the core portion and a relative refractive index difference Δ between the core portion and the cladding portion are present within a range where Rn, which is a ratio of a Rayleigh scattering coefficient Rsmf of a single mode optical fiber and an effective Rayleigh scattering coefficient Reff of the hole-assisted fiber, is equal to or less than 0.92.

    Optical fiber evaluation device and optical fiber evaluation method
    4.
    发明授权
    Optical fiber evaluation device and optical fiber evaluation method 有权

    公开(公告)号：US12085749B2

    公开(公告)日：2024-09-10

    申请号：US18009784

    申请日：2020-06-24

    申请人： NIPPON TELEGRAPH AND TELEPHONE CORPORATION

    发明人： Nobutomo Hanzawa ,  Takashi Matsui ,  Yuto Sagae ,  Kazuhide Nakajima

    IPC分类号： H04B10/00 ,  G02B6/02 ,  H04J14/00

    CPC分类号： G02B6/02042 ,  G02B6/02342

    摘要： The purpose of the present invention is to provide an optical fiber evaluation equipment and an optical fiber evaluation method that evaluate the center of a cladding of an MCF and a deviation of the center of each core of the MCF from a design value with ease and high accuracy.
    The optical fiber evaluation equipment according to the present invention approximates the outside diameter of a cladding by a circle, based on a cross-sectional image of an MCF, and determines the center of the circle as the center of the cladding. In addition, the optical fiber evaluation equipment according to the present invention obtains the center coordinates of cores with an origin at the center of the circle, rotates the cross-sectional image so as to minimize a difference between the center coordinates and design coordinates of each core, and derives the minimum value thereof as the amount of deviation of the center of each core.

    Acoustic mode propagation speed measurement method and acoustic mode propagation speed measurement device
    5.
    发明授权
    Acoustic mode propagation speed measurement method and acoustic mode propagation speed measurement device 有权

    公开(公告)号：US11815421B2

    公开(公告)日：2023-11-14

    申请号：US17434949

    申请日：2020-02-19

    申请人： NIPPON TELEGRAPH AND TELEPHONE CORPORATION

    发明人： Yuto Sagae ,  Takashi Matsui ,  Kyozo Tsujikawa ,  Kazuhide Nakajima

    IPC分类号： G01M11/00

    CPC分类号： G01M11/319

    摘要： An objective is to provide an acoustic mode propagation speed measurement method and an acoustic mode propagation speed measurement device capable of measuring a propagation speed of an acoustic mode without cutting or processing an optical fiber wire.
    According to the present invention, an acoustic mode propagation speed measurement method includes: acquiring a frequency shift spectrum of Brillouin scattered light generated in an optical fiber; fitting the frequency shift spectrum using a Gauss function; acquiring a spectral full-width at half maximum w from a fitted curve using the Gauss function; and calculating a propagation speed VA of an acoustic mode of the optical fiber by substituting the acquired spectral full-width at half maximum w into a linear function of the spectral full-width at half maximum w and the propagation speed VA of the acoustic mode.